Means for rapidly transmitting telegrams.



No. 662,020. Patented Nov. 20, 1900;

A. POLLAK & J. VIRAGL HE ANS FUR BAPIDLYYTRANSMITTING TELEGRAIIS.

I (Applicltion filed Kay 9, 1899.)

(N0 H BL) 3 sheetsshaet I.

INVENTORS: wzw 27? 2 5 No. 662,020. Patented Nov. 20, I900. A. POLLAK & J. VIRAG.

MEANS FOR RAPIDLY TRANSMITTING TELEGRAMS.

(Application filed May 9. 1899.;

(No Model.)

3 SheetsSheet 2.

INVENTORS: M0 WM w/ f #4 QQLM Patented Nov. 20, I I900.

A. POLLAK & J. VIRAG. MEANS FOR RAPIDLY TRANSMITTING TELEGRAMS.

(Application filed. May 9, 1899.) 3 Sh'eets-Sheet 3.

(No Modei.)

INVENTORS: J b/m z/ zzzzw By Azzowzeys, mam/w l l l l UNITED STATES PATENT OFFICE.

ANTON POLLAK AND JOSEF VIRAG, OF BUDA-PESTII, AUSTRIA-HUNGARY,

ASSIGNORS OF ONE-HALF TO VEREINIGTE ELEKTRIOITATS AOTIEN- GESELLSCHAFT, OF SAME PLACE, AND FRIEDRICH SILBERSTEIN, OF

VIENNA, AUSTRIA-H UN GARY.

MEANS FOR RAPIDLY TRANSMITTING TELEGRAMS.

SPECIFICATION forming part of Letters Patent No. 662,020, dated November 20, 1900.

Application filed May 9,1899. Serial No. 716,080. (No model.)

To (.l/ZZ whom it may concern Be it known that we, ANTON POLLAK and JOSEF VIRAG, residing at Buda-Pesth, in the Empire of Austria-Hungary, have invented certain new and useful Improvements in Means for Rapidly Transmitting Telegrams, of which the following is a specification.

This invention relates to automatic telegraphy, and has for its object a more rapid transmission of telegraphic messages than has been hitherto attained.

According to our invention the transmission is effected by automatic means, as by a prepared strip of paper traveling through a suitable transmitter, whereby electrical impulses are sent over the line to the receiving instrument, which consists of an electromagnetic vibrator having suitable means for recording its vibrations, preferably after the manner of a recording mirror-galvanometer that is to say, the vibrations of the receiver are communicated to a mirror to oscillate it, and thereby deflect a beam or ray of light, which is received and photographically recorded upon a photosensitive sheet or strip. The pulsations transmitted are of uniform duration, but may differ either in sign or intensity. The vibrator of the receiving instrument vibrates in harmony with these impulses,vibratingin one direction or the other, according to their sign and to an extent depending upon their intensity.

It is a characteristic of our invention that the duration of the impulse so nearly coincides with the period of one complete vibra tion of the vibrator of the receiver as to suppress supplementary vibrations,which would otherwise tend to confuse the record.

Our invention also provides certain accessory means for accentuating the sharpness of the record, increasing the speed of transmission, and overcoming the self-induction and capacity of the line.

Our invention allows the transmission of telegrams with aspeed hitherto unknown and by means of simple, compact, and inexpensive apparatus.

The special construction of the apparatus hereinafter described is of secondary consideration, the invention residing in the novel means employed for availing of such apparatus for the purpose of telegraphing.

Referring to the drawings illustrating our invention, Figure 1 is a top View of the preferred form of apparatus for the receivingstation. Fig. 2 is a side elevation thereof. Fig. 3 is a diagram illustrating the variations produced by the vibrating diaphragm. Fig. 4. is a side elevation of the system employed by us in carrying out our invent-ion. Fig. 5 is a top plan view thereof. Fig. 6 is a view of the perforated strip used at the transmission-station, and Fig. 7 is a view of the record obtained at the receiving-station. 8, 9, and 10 illustrate in detail one form of receiving instrument, of which Fig. 8 is a transverse section, Fig. 9 is a plan with the mirror removed, and Fig. 10 a fragmentary perspective view. Figs. 11 and 12 show an other form of receiving instrument, Fig. 11 being a mid-section and Fig. 12 a sectional plan with the mirror removed. Fig. 13 is a diagrammatic elevation of the transmitting apparatus similar to that shown in Fig. 4 and illustrating means for regulating its speed. Fig. 14 is a diagram illustrating the circuit arrangement-s. Fig. 15 is a diagram of a transmitter adapted'to'transmit impulses differing both in sign and intensity. Fig. 16 is a view corresponding to Fig. 7 and showing the record obtained at the receiving-sta- 'tion upon using the transmitter illustrated in Fig. 15.

Referring to Figs. a and 5, which show one embodiment of our invention, a and 5 show the transmitting apparatus and 4 and 5 the receiving apparatus which we prefer to employ. The transmitting apparatus here shown consists of a pair of rotating rollers 13 g, which are designed to feed a strip of paper, perforated according to the message to be transmitted, in the well-known manner, underneath brushes 7tm, whereby a current is led from the batteryX either positive through the brush or negative through the brush m to the conducting supporting'plate Z, ac-

cording as the brush or the brush in comes in contact with this plate through the perforations of the strip.

A form of perforated paper strip especially suited for our purpose is shown in Fig. (5. As there shown the perforations are not circular, but oblong, whereby through the insured contact of the brushes the circuit making and breaking take place in a more precise and positive manner. The arrangement of the perforations is such that those serving for producing the positive and negative impulses are respectively arranged in special lines. In Fig. 6 the first four letters of the alphabet are illustrated to correspond to the Morse signs. The openings in the upper line represent the dashes, and those in the lower line represent the dots.

The receiving apparatus shown comprises an electromagnetic vibrator or oscillometer, being preferably a telephone A, having a vibrating diaphragm M, which is connected to a small mirror a, so that the vibrations of the diaphragm shall oscillate the mirror. The telephone-coil is or may be in the line-circuit. A ray of light from a source F is projected through an opening in a stationary screen 0 upon the mirror at, which is preferably a concave mirror, by which is reflected a sharp image or point of light on a moving strip or sheet D of photosensitive paper or film. The current impulses coming from the transmittingstation enter into the coil of the telephone A and vibrate its diaphragm.

When a current impulse from the transmittingstation reaches the coil of the telephone, the telephone-diaphragm is moved or vibrates, and the mirror (L, which is connected therewith, responds to such impulse. The oscillating mirror causes a change in the direction of the reflected ray of light, so that the point of light on the sensitive strip moves to an eX- tent depending on the extent of movement of the diaphragm. In consequence of the rapid oscillations of the telephone-diaphragm and the small weight of the mirror a the oscillations of the latter occur rapidly, and the range of oscillations or vibrations is very considerable, even with a weak current.

In Figs. 8, 9, and 10 one suitable construction of the telephone is shown on a larger scale. In these figures the telephone A comprises a shell A, magnet A and diaphragm M. Fixed to the shell of the telephone is a permanent magnet N S, which, as shown in Fig. 10, is formed at one pole N with sharp edges or points 1. The opposite pole S carries a delicate spring 4, formed at its free end with a sharp edge 3. Between the free end of the spring 4t and diaphragm M is interposed a light rod 5. The mirror CLiS provided with an iron back and is held on the edges 1 and 3 by magnetic attraction. The movements of the diaphragm are transmitted to the mirror through the rod 5, which moves the spring 4. As the edges 1 and 3 are in close proximity, relatively great movements are given to the mirror by the comparatively small movements of the diaphragm.

To attain the object in view, it is not absolutely necessary to employ the above described retlector-telephone, as any rapidly-oscillating mirrorgalvauometer or so called oscillometet may be used. It is not necessary to here describe such oscillometers, as they are well known. Blondell in the Eleotricicm, Vol. 30, p. 571, describes the most important types of such apparatus.

We show in Fig. '7 a portion ol a record corresponding to the transmitting-strip shown in Fig. 6, this record being that which should be produced by an oscillating ray of light the movements of which are caused by the telephone or oscillometer herein described. The telephone-diaphragm or oscilloineter is not, however, capable of exactly reproducing the currentimpulses owing to its tendency when moved by a current impulse to continue in vibration according to its own characteristic rate of vibration or pitch. Hence the tendency is that each impulse shall be lollowed by a series of diminishing oscillations, which would confuse the record and render it unintelligible. Our invention avoids these supplementary oscillations and produces clear and well-defined signs corresponding closely to the ideal signs shown in Fig. 7, while the current impulses producing them maybe sent from the transmitting-station with great rapidity. To make this clear, we will refer to the diagram Fig. 3, where the sinuous line 1 2 3, 810., represents the vibrations cl a diaphragm attracted from its position of rest (indicated" at line D) by a current of a certain strength, which should deflect the diaphragm to the position indicated by the line 0. The diaphragm starting at 1 is attracted toward the line 0, but swings across this line by its momentum in one complete semivibration to the point 2, whence it returns in a diminishing oscillation to the point 3 and continues to vibrate with lessening amplitude, following the diminishing oscillations shown until it finally comes to rest on the line 0. Such is the performance of an u n m ufl'led diaphragm which is free to vibrate in its own natural pe riod. Now if the diaphragm were mu l'tled or damped, so as to retard its vibration, it would move gradually from the initial position b to the position 0 in the manner indicated graphically by the curved full line d. Such a muffled diaphragm would produce signs free from confusing vibrations and approximating closely enough to the true curves shown in Fig. 7; but the rate ottransmission would be very slow, because of the sluggish response of the diaphragm to the successiveim pulses. If, however, with an nu.- mnliied diaphragm the current impulse starting at 1 is cut off at 3, where the diaphragm having execn ted one complete oscillation has returned nearest to its original position, the after vibration, due to the further movement of the diaphragm from the point 3 to its norl TO mal position Z), is so nearly devoid of energy that in practice it may be entirely neglected, and it does not interfere with the true reproduction of the signs.

Our invention accordingly is distinguished by such proportioning of the duration of the transmitted impulses to the natural period of vibration of the vibrating member of the receiving instrument or oscillometer that the duration of theimpulse shall so nearly correspond to one complete oscillation of the receiver as to practically suppress any deleterious after vibrations thereof. By this simple means alone, whereby for the first time in the art we adapt the rate of transmission to the natural period or typical rate of vibration of the receiver, so that the duration of each sign corresponds to one oscillation thereof, we increase the speed of transmission at least three times over what would be possible if the vibrating member or diaphragm of the receiver were mechanically damped.

WVe may carry our invention into practice in two ways: first, by regulating the speed of transmission in order to bring it into harmony With the natural rate of vibration of the receiver or, second, by adopting a fixed speed of transmission and regulating the rate of vibration of the receiver.

The first method may be variously performed-as, for example, by accelerating or retarding the speed at which the perforated strip is drawn through the transmitting instrument. One way of accomplishing this is shown in Fig. 13, where the electromotor r,

1 which drives the rollers 19 q of the transmitter, is provided with means for regulating its speed. The motor is here shown as fed from main circuit wires or leads 1 and r under a constant electromotive force, a rheostat r being introduced in the branch circuit feeding the motor, whereby the current through this branch circuit energizing the motor may be controlled, this being a common and wellknown means for varying the speed of electromotors. The speed of the strip must be controlled proportionally to the size of its perforations, so that the current impulses shall last only so long as is necessary for the telephone-diaphragm or other oscillat ing-member of the receiver to return in consequence of its own vibration to the closest proximity to its position before the current impulse.

The second method may be performed by any means adapted to modify the rate of vibration of the diaphragm or vibrating member of the receiving instrument. To observe this condition, it is necessary that the strip of perforated paper at the transmitting-station should move at a certain constant speed. One means for thus controlling the receiver is shown in Figs. 11 and 12, where the vibrating member is a disk M, which is fixed upon wires 8 8, which are stretched across the shell of the telephne, and the tension upon these wires is adjustable by means of a screw 7. By turning this screw the tension of the wires, and consequently their rate of vibration, is altered, whereby the instrument may be adjusted to vibrate at a rate so proportioned to the duration of the impulses that the diaphragm shall execute one complete oscillation to each impulse.

Both methods of regulation just described involve the necessity of a practically uniform rate of transmission, which in practice would necessitate the mploymentof precise-working motors.

A further feature of our invention facilitates attaining the desired object and enables even a higher speed of transmission to be maintained. According to this feature of our invention we shorten the duration of the impulse to somewhat less than one complete oscillation of the diaphragm or vibrating member of the receiver. This is easily attained by moving the strip at a greater rapidity through the transmitter than has been heretofore described. We also prolong the effect of the impulse upon the receiver by employing a condenser connected in parallel to the receiving instrument, as shown at n in Fig. 5. As a consequence of this arrangement when the circuit is closed part of the current is collected in the condenser, which after the current is interrupted, discharges itself through the coil ofthe receivinginstrument or oscillometer. For example, the duration of the impulse may equal two-thirds of the time of a complete oscillation of the receiving instrument, so that in Fig. 3 the impulse may cease at the point 4. During this time it has charged the condenser, the discharge of which through the receiving instrument prolongsthe etfeet of the impulse to approximately the point 3. By employing a condenser of suitable capacity the diaphragm or vibrator of the receiver is caused to return to its original position without any supplemental oscillations. This expedient so sharpens the record as to bringit practically to the form shown in Fig. 7 and permits the adoption of a speed of transmission which is approximately double that attainable by the firstdescribed means.

A further feature of our invention applies to the transmission over long lines. In order to obtain a rapid succession of current impulses over long lines notwithstanding the capacity and self-induction of the line, we have found it to be advantageous to arrange in parallel with the line one or more self-induction coils, an example of which is shown at 0 in Fig. 5. The effect. of such coil is to cause after each current impulse a second impulse in the opposite direction over the linecircuit. By properly proportioning the capacity|t f this coil totheself-inducl ion capacity and resistance of the line we are ableto secure a sharp, clear, and legible record over lines of great length.

The circuit arrangements will be more apparent from the diagram Fig. 14-, where the solid arrows show the direction of the impulse represent the dots from the transmitting-battery X, the broken arrows show the discharge from the condenser 11, and the dotted arrows show the discharge from the self-induction coil 0.

In the arrangement thus far described only positive and negative current impulses are used in transmitting. If desired, however, current impulses of different strengths or intensities may be used insteadfor example, a positive impulse of a certain intensity to represent a dot and a positive impulse of a certain increased intensity to represent a dash. By using simultaneously current impulses of different directions and strengths the number of signs may be considerably diminishedas, for instance, in such a manner that the weaker positive impulses may f the Morse signs and the stronger positive impulses may represent the dashes, while the weaker negative impulses may represent two dots and the stronger negative impulses two dashes, as shown in 16, which corresponds otherwise to Fig. 7. For this purpose the number of brushes and of openings in the transmittingstrip will be correspondingly chosen. One means for carrying out this feature is shown in Fig. 15, where the line-battery X is so divided as to give positive and negative impulses of ditferent strengths, the weaker positive battery being connected to the positive brush it and the stronger to the positive brush le while the weaker negative battery is connected to the negative brush m and the stronger to the negative brush m the strip of prepared paper having four corresponding rows of holes. In Figs. 15 and 1.6 the signs +1 1 indicate the'weaker positive and negative currents, while +2 and 2 indicate the stronger positive and negative currents.

That the mirror of the telephone or oscillometer may be as small as possible, and consequently light, and so that a less strong source of light may be employed a diaphragm O with a long narrow slit instead of a circular h'ole may be used in front of the source of light F, as shown in Fig. 1. The beam of light thus formed is focused to a point by a lens g, which has a short focus, and is placed as near possible to the sensitive strip of paper. The mirror maybe even smaller if a small cylinder-lens g of short focus is placed in front of it, the generatrix of which is parallel to the plane of vibration of the ray of light and which is placed at such a distance from the mirror that; the image produced. b 7

it shows on the top of the said mirror. The ray of light reflected from the mirror passes again through the lens g.

The photographic record may be made upon any suitable strip or sheet caused to travel in any suitable manner in a direction crossing the oscillations of the point of light. Thus the signs constitute a sinuous line, which after the strip has been developed and fixed produces a record exactly indicating the contents of the telegram sent from the transmitting-station. The sensitized paper may be placed around a rotating and forwardly-moving drum H, as shown in Figs. at and 5, so that the record extends spirally around it. This arrangement is of advantage for noncontinuous working, as during the changing of the strip of sensitive paper after it has been fully used at one station this station may be occupied in sending telegrams to the transmitting-station, or the line maybe used forsending to a third station. Our invention may, however, be used for continuous working in any suitable wayas, for example, by coiling a long hand D in the manner shown in Fig. 1 or in such manner that the signs are disposed perpendicularly to the direction of travel of the band. In such case the derGlOlJlllg and fixing of the sensitized strip may be easily and simply effected by passing it through suitable vessels which contain the required developing and fixing solutions.

It is not essential to our invention that the identical impulses sent from the transmitter shall be the ones which directly affect the receiver, it being within our invention to employ any system found in the telegraphic or telephonic arts whereby electric impulses transmitted from a transmitting-station shall in tluence or determine impulses which at the receiving-station shall themselves act upon the receiving instrument. It is also to be understood that the duration of the impulses which is essential to our invention is that which directly influences the receiving instrument. Thus in the case already explained where a condenser is used the transmitted impulses are shorter than those which would best influence the receiver; but these impulses are prolonged in their effect upon the receiver by the action of the condenser.

While the preferred and most perfect mode of practicing our invention involves that the impulse actuating the receiver shall terminate at the end of one complete oscillation of its vibrator, itis within our invention that such impulse may include a definite multiple of such duration, so as, for example, to discontinue the impulse affecting the receiver at the end of the second complete oscillation of its vibration-that is to say, at the point 5 in Fig. 3-which would modify the system herein described to the extent merely of duplicating each sign. This, although it would necessitate operating at a slower speed of transmission, would nevertheless provide a system having a higher rate of transmission than other systems of telegraphy heretofore known,

It is within our invention to employ any suitable means known in the art for transmitting current impulses of proper strength and duration and in proper succession over the line, our invention not being limited to the combination of battery and circuit-closer (the latter comprising a suitably-perforated strip) which we have herein shown and doscribed, as this is but one of several means for transmitting suitable eutrent impulses that are available in practicing our invcntion.

The system of telegraphy provided b y our invention is to be clearly distinguished from socalled harmonic tcl graphs. In these latter the same line is utilized to place several transmitters at one station in communication with several receivers at the otherstation by giving the receivers different rates of vibration and tuning the transmitters to transmit impulses over the line at varying rates (JOll'GSPOlldltlg to different in usieal notes, the rate of vibration of each transmitter agree ing with that of the receiver with which it is to communicate. Thus in transmitting the Morse alphabet the transmitter will to form a dot impose a certain succession of impulses upon the line and to transmit. a dash will impose upon the line a longer-succession or duration of such impulses, so that. each sign which is transmitted is composed of a considerable number of impulses. In our system, on the contrary, every impulse is utilized to transmit a sign, or, in other words, each sign transmitted requires only one impulse or current wave as the medium of its transmission. Consequently by our system we are enabled to transmit with aspeed proportionate to the the harmonic principle beingresorted to solely for the accomplishment of multiplex transmission.

We claim as our in ven tion the following-defined novel features, substantially as hereinbefore specified, namely: I

1. A means for rapid telegraphy, comprising the combination of a transmitter and a vibratory receiver, the transmitter adapted to send impulses which shall affect the receiver for a duration so nearly corresponding to its period of oscillation as to substantially suppress supplementary oscillations thereof.

2. A means for rapid telegraphy, comprising a transmitter adapted to send electric impulses, combined with a vibratory receiver having a definite rate of vibration, the trans- Initter and receiver being so synchronized that the duration of each impulse aifecting the receiver shall correspond to one complete oscillation thereof.

3. A means for rapid telegraphy comprising a transmitter adapted to send electric impulses, combined With a vibratory receiver having a definite rate of vibration, and means for varying the relative periods of said transmitter and receiver, to enable them to be so synchronized that the duration of each impulse affecting the. receiver shall correspond to one complete oscillation thereof.

t. A means for rapid telegraphy comprising a transmitter adapted to send electric impulses, combined with a vibratory receiver i: a ving a definite rate of vibration, and means for \U-tnving the duration of th nnnulses affecting the receiver adapted to so s3 HclllOlllZG the transmission to the period of the receiver that the duration of each such impulse shall correspond to one complete oscillation of the reeeivetz,

5. A means for rapid telegraphy comprising a transmitter adapted to send electric impulses, combined with a vibratory receiver having a definite rate of vibration, a motor for driving the transmitter, and means for vary ing the speed of the transmitter, whereby it may be so synchronized to the receiver that the duration of each impulse shall correspond to the period of oscillation of the receiver.

6. A means for rapid telegraphy comprising a transmitter adapted to send electric impulses, combined with a vibratory receiver having a definite rate of vibration, and a condenser connected in parallel with the receiver and adapted to be charged during each transmitted impulse, and by its discharge to prolong such impulse through the receiver.

7. A means for rapid telegraphy comprisin; a transmitter adapted to send electric impulses, combined with a vibratory receiver having a definite rate of vibration, the transmitter and receiver being so synchronized that the duration of each impulse shall be, shorter than one complete oscillation of the receiver, and a condenser connected in parallel with the receiver, and adapted to be charged during each transmitted impulse, and by its discharge to prolong such impulse through the receiver.

8. A means for rapid telegraphy comprising a transmitter adapted to send electric impulses over a line, combined with a vibratory receiver having a deft nite rate of vibration, and a selfinduction device connected in parallel with the transmitter, the transmitter and receiver being so synchronized that the duration of each impulse shall correspond to the period of oscillation of the receiver.

9. A means for rapid telegraphy, comprising the combination of a transmitter and a vibratory receiver, the transmitter adapted to send either positive or negative impulses which shall affect the receiver for a duration so nearly corresponding to its period of oscillation as to substantially suppress supplementary oscillations thereof.

10. A means for rapid telegraphy, com prising the combination of a transmitter and a vibratory receiver, the transmitter adapted to send impulses of uniform duration and varying intensity, their duration being such as to affect the receiver for a time so nearly corresponding to its period of oscillation as to substantially suppress supplementary oscillations thereof.

11. A meansfor rapid telegraphy, comprising the combination of a transmitter and a vibratory receiver, the transmitter adapted to send either positive or negative impulses of uniform duration and varying intensity their duration being such as to affect the receiver for a time so nearly corresponding to its period of oscillation as to substantially suppress supplementary oscillations thereof.

12. A means fo rapid telegraphy comprising a transmitter adapted to send electric impulses of substantially uniform duration in rapid succession, combined with a vibratory receiver having a definite rate of vibration, and com prising an elastic vibrating part, an oscillating mirror, a source of light, and means for photoc'raphically recordi us the deflections of the beam of light reflected from said mirror.

13. A means for rapid telegraphy com prising a transmitter adapted to send electric impulses of substantially uniform duration in rapid succession, combined With a receiver comprising an elastic vibrating part, a mirror oscillated by the vibrations thereof, a means for directing a beam of light upon said mirror, at photosensitive surface receiving the beam reflected from said mirror, and means for moving said surface, Wherebyit records the oscillations of the receiver.

14. A means for rapid telcgraphy comprising a transmitter adapted to send electric impulses of substantially uniform duration in rapid succession, combined with a receiver comprising an electromagnet, an elastic vibrating diaphragm therefor, a mirror oscillated by the vibrations of said diaphragm, means for directinga beam of light upon said mirror, a photosensitive surface receiving the beam reflected from said mirror, and means for movin said surface, whereby it records the oscillations of the diaphragm.

15. A receiver com prisincan elastic vibrating part, a mirror oscillated by the vibrations thereof, means for directing a narrow beam of light upon said mirror, a photosensitive surface receiving the beam reflected from said mirror, and a cylindrical lens arranged to converge said beam of light to a point at said surface combined with a transmitter adapted to send a rapid succession of current impulses of substantially uniform duration.

In Witness whereof we have hereuntosi ned our names in thepresence of two subscribing witnesses.

ANTON POLLAK. JOSEF VIRAG. Witnesses:

FRANK DYER Cnns'rnn, LASO limos. 

